Field of the Invention
The present invention relates to a production method of a rotary electric machine.
Related Art
Conventionally, rotary electric machines such as electric motors and power generators that include a stator and rotor have been known. The stator of a rotary electric machine is usually produced in the following way.
First, a plurality of coil elements in which a plurality of electrical conductors is bundled to form a substantially U-shape is prepared. Next, the plurality of coil elements thus prepared is aligned in an annular shape while layering in a circumferential direction, and in this state, the leading end part of each electrical conductor is inserted in each slot provided in an annular shape to the stator core. Next, after the leading end part of the plurality of electrical conductors projecting from each slot is twisted and bent, the leading end parts thereof are joined. The stator of a rotary electric machine is thereby produced.
However, as a method of joining the leading end parts of the plurality of electrical conductors, TIG welding is widely carried out (for example, refer to Patent Document 1). However, in TIG welding, it is necessary to reliably make the earth electrode contact each electrical conductor. For this reason, as a result of the number of earth electrodes also increasing as the number of electrical conductors increases, the device configuration becomes complicated.
Therefore, in recent years, laser welding is being considered as a method of joining the leading end parts of a plurality of electrical conductors. With laser welding, in order to obtain a large melt area in the joining face between the leading end parts thereof, a laser is irradiated along the joining face. According to this laser welding, earth electrodes are unnecessary, and high energy efficiency is obtained.
[Patent Document 1] Japanese Unexamined Patent Application, Publication No. 2000-350421